Printing-press



F. J. LEHR.

PRINTING PRESS.

APPLICATION FILED Aun-L27. 1917.

Patented Aug. 31, 1920.

2 SHEETS-SHEET I.

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F. J. LEHR.

PRINTING PRESS.

APPLICATION FILED Aural?, 19u.

1,351,175. PanIedAug. 31,1920.

2 SHEETS-SHEET 2.

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nutren stares Nr orties.

FRANK J. LEER, OI"` ROCHESTER, NEW YORK, ASSIGNOR TO STECHERLITHOGRAPHIC COMPANY, OF ROCHESTER, NEVJ YORK, A CORPORATION OF NEWYORK.

PRINTING-PRESS.

Application led August 27, 191'?.

To all whom 15 may concern:

Be it known thatl, FRANK J.' Lutin, of Rochester, in the county ofMonroe and State of New York, have invented certain new and usefulImprovements in Printing- Presses; and I do hereby declare the followingto be a full, clear, and exact description of the same, reference heilighad to the accompanying drawings`r forming a part of this specification,and to the reference-nu-y merals thereon.

My invention relates to aprinting press and particularly to a shiftingmechanism for the press cylinders and has for its object toautomatically effect the sepa lation of the impression and printing, orform, cylinders by the use of electric circuits of relatively highandlow voltage currents in the absence of a sheet from the grippersduring the feeding process. Another object of the invention is to effectthe closing of a relatively low voltage electric circuit in which isarranged a magnet adapted to effect the closing of a relatively highvoltage circuit,

insulated from the press, and serving to operate means for controllingthe shifting of one of the press cylinders by the operation of anotherin absence of a sheet from the grippers thereof. To these and other endsthe invention consists in certain improvements and combinations ofparts, all as will be hereinafter more fully described, the novelfeatures beingpointed out inthe claims at the end of the specification.

In the drawings:

Figure l is a. side elevation illustrating one embodiment of theinvention with the.

cylinders shown in normal position, and

Fig. 2 is a similar view illustrating` the position of the cylindershifting mechanism after the electric circuit-s have been closed toeffect operation of the same.v Similar reference characters throughoutthe drawings indicate similar parts.

In printing and lithographie presses it is necessary whena sheet hasbeen missed in the feeding to at once separate the cylinders. lf thiswere not done an impression would be delivered from the printing surfaceto the impression cylinder, and the succeeding sheet would thereby havean ims Specification of Letters Patent.

Patented Auu 31, 1920.

serial No. 185,347.

pression in reverse print upon the baclr as well as the regularimpression on the face. lt is, therefore, necessary to providemeans forautomatically separating the cylinders in cases where sheets are missedin the feeding process. Heretofore in electrical. devices provided forthis purpose the trouble experienced has been that'the strength of thecurrent required to perform the necessary operations has been greaterthan the operator could stand, in cases where the current leaked throughthe press, the result being that the workmen often become violentlyshocked while manipulating the machine. lt is to overcome these andother disadvantages of the present day shifting mechanisms that theinvention set forth herein is intended to accomplish.

ln the embodiment shown, l represents a portion of the frame of aprinting-press upon which the cylinders 2 and 3 are mounted, comprisingrespectively the impression and plate, or printing cylinders. Aplurality of grippers el are mounted on the shaft 5 of the impressioncylinder at equal distances apart, the points of the grippers whenclosed serving to hold the sheets upon the contacts 6 supported by theinsulation 7 on the bars S. rlfhe contact 6 is connected with thesurface 9 of the cylinder 2 by means of the wire l0, while duringrotation of the cylinder said surface engages the contact ll of theframeas shown in Fig. E2, thereby completing the circuit throughconductor l2, battery 13, conductor 14, magnet 16 and conductor i7. Thusit will be seen that the gripper et and contact 6 form the means by whici the absence of the sheets is detected. lf there is no paper betweenthese points when the gripper descends the magnet 16 will be energizedto draw the armature 18 away from the insulated point 19, against theaction of the spring 20, and into engagement with the contact 2l,thereby closing the main circuit, which is the tripV controllingcircuit, through conductors 22 and 23, magnet 2st and conductor 25.

The plate, or operatingl cylinder, 3 is provided with an eccentricbearing 2G, to the arm of which is pivotally connected the downwardlyextending rod Q7 arranged to lll@ project loosely through the guide 28on the press frame l. The rod is held in normal position as shown inFig. 1, by the compression spring 29 mounted between th'e guide 28 andadjustable stop 30 on the rod. The

rod carries an adjustable collar, or projec-V crank is pivoted upon thelever 34, which is pivotally mounted upon the press frame at 35, saidlever being held in normal position by the spring 36 having one endconnected with'the rearwardly extending arm 37 and the other with thestop 38 on the frame. The lever is provided with a lug, or proj ection39, extending into the notch 40 oit' the bell crank constituting stopsto limit its'up and down movement. When the cylinder 2 is revolving inthe direction `indicated by the arrow the cam 41 will engage the roller42 of the lever 34 `and depress the latter, and if the paper is betweenthe gripper 4 and contact 6 the arm 32 of the bell crank will escape theprojection 31, thus allowinothe rod 27 to remain at normal position.owever, in the absence of a sheet between the gripper 4 andrcontact 6'the low voltage batj tery circuit will serve to effect a closing of beforced down by the lever 34 when the latter is operated bythe cam 4l.This will effect, Vby means of the eccentric bearing 26,

a movement of the printing cylinder 3 in a l direction away from theimpression cylinder 2, as indicated by Fig. 2, in which position it willremain as long as the battery circuit is closed.' By this means it willbe seen that a relatively high voltage circuit may be used for efectin'gthe operation of the cylinder trip mechanism without danger of throwingthe current into the press and injuring the operator, while a current ofrelatively low Vvoltage may be used both for detecting the absence of asheet from the grippers and i'or automatically closing the high voltagecircuit which controls the tripping mechanism.

I claim as my invention:V

Y l. In a printing press, the vcombination of a frame, an impressioncylinder rotatively 'mounted therein and adapted to receive a worksheet,a rotatable plate cylinder normally in contact with said impressioncylin-V der, a rock arm pivoted to the frame, means actuated by saidimpression cylinder for rocking said arm, andan electrically controlledbell crank pivoted Vto said rock arm and adapted to separate saidcylinders in the absence of a work sheet on the impression cylinder.

2. in a printing press, the combination of a frame, an impressioncylinder rotatively mounted therein and adapted'to receive a work sheet,a. plate cylinder coperating with said impression cylinder, a rodconnected with said plate cylinder ior'shifting the latter away from theimpression cylinder, a projection on said rod, a. bell crank Y havinganarmjnormallyout of position to engage said projection but movable toaposition to'engage said projection and shift said cylinder, and electricmeans comprising a circuit adapted to be closed in the labsence ofasheet from the impression cylinder for moving said bellcrank intoposition to engage said projection.

3. In a printing press, the combination with impression and platecylinders adapted to operate upon a work sheet, of automatic means forseparating the cylinders in the absence of Va work sheet, said meanscomprising grippers and complementary contacts on said impressioncylinder adapted to engage a work sheet, an electric circuit comprisinga relay adapted to operate when the grippers engage saidV complementarycontact in the absence of a work sheet, a source of electriccurrent forsaid circuit of such low tension as to be inappreciable to the humanbody, a second electric circuit of relatively higher tension actuated bysaid first circuit and mechanism fory separating the impression andplate lcylinders when said second circuit is energized.

4. In a printing'press thecombination with a frame of impressionantiplate cylins ders, automatic means for separating the cylinders in theabsence of a work sheet, said means comprising an eccentric bearing forsaid plate cylinder, a slidable rod attached thereto for moving thesame, a projection on said rod, a lever pivoted to said frame, a camrotatable with said impression cylinder, a roller onsaid lever forcoperation with said cam, a bell crank lever pivoted to one end of theiirst mentioned lever, normally free from coperation withV saidprojection on said rod, and provided with a notch adjacent the pivot, aprojecting lug on said lever in coperation with said notch to limit thepivotal movement of said bell crank lever and an electric magnet fixedrelative to said frame and adapted to engage one arm of said bell cranklever when energized, the other arm oit' said bellV crank leverbeingadapted to engage the projection on said rod to move the same whensaid magnet is energized. Y Y

5. V1n `a printing press the combination with a frame of impression andplate cylinders adapted to operate upon a work sheet, Y

ders in the absence of a Work sheet, said means comprising eccentricbearings for said plate cylinder, a slidable rod attached there to formoving the same, a projection on said rod, a lever pivoted to saidframe, a cam rotatable on said impression cylinder, a roller on saidlever in coperation With said cam aiid an arm pivotally attached ,toSaid lever and normally not engaging said projection on said rod, meansfor moving said 10 arm on the lever.

FRANK J. LEHR.

